Anaerobes, bacteria that thrive in the absence of oxygen, are now known to be major contributors to disease as well as critical to human health. While regional societies focused on anaerobe bacterial science exist in select locales abroad (e.g., Britain, Japan), the Anaerobe Society of the Americas is the only United States-based Society devoted to the basic and clinical science of anaerobes. Further, the Anaerobe Society of the Americas has long had an active international membership with representation from more than 30 countries at the 2010 Biennial Congress. The long term goal of the Anaerobe Society of the Americas and its biennial conference (founded in 1992) is to promote health and advance science through the study of anaerobic bacteria and their environments. This R13 is submitted to provide support for the 11th Biennial Congress of the Anaerobe Society of the Americas to be held in June, 2012, where cutting edge science relevant to anaerobic bacteria will be presented. The specific aims of the 11th Biennial Conference are: 1) to stimulate interchange among anaerobe biologists from all disciplines (medical, dental, veterinary, microbiology and basic sciences); 2) to assess the current understanding of the human microbiota and its role in disease; 3) to discuss controversies and advances in disease induction by Clostridium spp. (including Clostridium difficile); and 4) to probe emerging mechanisms of action, health benefits and regulatory issues in probiotic development and clinical use. The 11th Biennial Congress will accomplish this goal through presentations by 26 domestic and international expert scientific speakers and a variety of presentation formats. The one-room, intimate nature of the conference fosters a hearty, person-to-person, interdisciplinary exchange between scientists who do not necessarily come together in another venue. Consistent with the goals of the NIH and NIAID, the 11th Biennial Congress of the Anaerobe Society of the Americas provides a unique opportunity to bring together the world's leading basic and clinical investigators in anaerobe bacterial science and its translation to advance studies with lasting impact on human health. PUBLIC HEALTH RELEVANCE: Anaerobes, bacteria that thrive in the absence of oxygen, are now known to be major contributors to disease as well as critical to human health. The Anaerobe Society of the Americas is the only domestic and international society devoted to the basic and clinical science of anaerobes. This conference provides a unique opportunity to bring together basic and clinical investigators in anaerobe bacterial science to advance studies with lasting impact on human health.